Projected-light picture screen



A. D. BRIXEY PROJECTED LIGHT PICTURE SCREEN Original Filed Agg. 27. 1920 PLAT! NIZE'D GLASS, 5

2, PYROXYLIN COMPOUND l, TRACLINCT CLOTH M mvaHToR BY a MATTORNEY latented Ayn. l4, 1925. 'UN'ITED STATES PATENT OFFICE.

AUSTIN DAY BRIXEY, OF GREENWIGH, CONNECTICUT, ASSIGNOR TO THE REPLITURA n CORPORATION, A CORPORATION OF NEW YORK.

I PROJECTED-LIGHT PICTURE SCREEN. Application filed August 27, 1920', Serial No. 406,395 Renewed April 4, 1924.

To all whom it may concern. j one side of the tracing cloth. is placed a coat- Be it known that I, Aus'rm DAY Bnrxnx, ing-2 of a compound of pyroxylin which is a citizen of the United States of America, compounded and applied in the following residing at the city of Gr renwich, countyof manner. 5 Falrfield, and State of Connecticut, have 1n- Amyl lanetatmnflgnu partsby Volume.

vented new and useful Improvements in Projiecltled-Light Pictur]?iv Screens, of which ggggi i g 97% 55? the o owing is a spec' cation. p This invention relates to means whereby gfi gfigg carbonate or 13 p y Weight 10 a plcture, image or des1gnmay be reprocamphor I partsbv Weight.

duced at a distance through the mstrumen- Refined gig 10 arts volume tality' of projected light, it being especially Benz-me II2: 20gartSb7Vo1ume:

adapted for use in connection with magic lanterns, moving picture projectors, etc. and to this should preferably be added a 15 In the Patent No. 1,20 l,401dated Novemtrace of methylene blue to produce a more her 14th, 1916, is shown a device of this perfect whiteness of the composition. The general character,the present invention havcompound thus produced is then mixed half ing to do with screens of the transmission an half wi h a thlnner 0f the following type as explained in the patent referred to. c mposltlon- 20 The main ob'ect of the invention is to pro- Thinner 'vide a icture Screen of the character indig 'i 7 g cated WhlCh shall produce an unusually 5 9 23 7 7 35 clear, soft and sharply defined picture. B o 20 A further object of the invention is to 2 23: 71o 27 Z 25 .provide a screen of the character indicated 1 which shall readily lend itself to processes The mixture thus secured is then flowed over $0 of manufacture. i. .1 a surface of the tracing cloth while it is Other and ancillary objects" of the invenmaintained in a osition of about 459 to tion'will appear hereinafter. the horizontal. The proper amount of the 30 In the accompanying drawing which illusmixture will then adhere to the surface of trates the invention, the figure shows an imthe tracing cloth and produce the coating 2 proved screen in section in its relationship shown in the figure, the coating having been to the projector and the eye of the observer, allowed to harden after application. Y The Y the two last being conventionally shown screen may then be placed in position as 35 and the thickness of the constituent parts shown in the drawing with the tracing cloth of the screen being exaggerated over actual toward the eye of the observer when an un-. conditions for the sake of clearness. usually distinct and soft picture will be ob- Referring to the drawing the eye of the served upon the operation of the projector. observer is indicated at a, the projector at b When the tracing cloth with its coating as 4 and the picture visualizing device or screen described is used alone, it is preferable that at c. The projector may be of any suitable the shiny side of the tracing cloth be the or well known construction. one to which the coating is applied so that The icture screen 0 comprises a sheet 1 the rougher side of the cloth will be toof tracing cloth. This tracing cloth may ward the observer, the reflection from the 45 be that commonlyin useby draftsmen which, surface of the device being thus lessened,

as is well known, comprises a fabric woven and the distinctness of the picture improved, of threads afterthe usual manner of weavover what would be the case if the shin side ing cloth to which is applied a composition of the cloth were nearer the observer. owwhich gives a smooth surface and- "yet is ever, if the coating were applied to the rough light transmitting to a sufficient extent to side of the cloth so that the shiny side of permit the draftsman to obey. e through the the tracing cloth were exposed, this shiny tracing cloth any objects beneath .it.v This surface could be dulled in any suitable manneed not be described in further detail as ner as by rubbing -it with cornstarch or in it is a product well known in the art. Upon any ot er suitable way. The reflection to screen is due ric in uxta-position the eye of the observer from the surface of thetracing cloth may be practically eliminated, and this is probably the most satisfactoryv method, by placing a plate 3 of platinized glas between the tracing cloth and the observers eye. This platinized glass may be of the samecharacter as described in my patent above referred to.

While the method just described gives very satisfactory results a small variation in the-thickness of the coating from that referred to, which would be obtained if the tracing cloth'were held at different angles fromth'at mentioned in applying the coating, or which might vary therefrom when applied in other ways, realization to a large extent of the advan-* ta ges of the screen, it being intended to indicate that-the precise thickness of the coating is not essential but may be varied siderable extent to suit different conditions. While I do not desire to confine myself to any particular theory 'of operation, it is my understanding that the excellence of the to the peculiarly efficient action of the coating in diffusing the light and so producing the picture or image, This very property, however, causes the light to be refracted into sidewise rays which interfere with each other and tend to produce indistinctness. lacing the woven fabto this medium, however, the threads of the fabric prevent this sidewise propagation of the-light rays and confine them to a path from the surface of coating which is substantially perpendicular to the surface of the screen upon The picture definite and properties of availed of so that the comthe coating are g What I claim is:

would still permit the bmation provides a means for producing an cise details of the composition of matters cited nor to the structure shown in the drawin l 1. A picture screen for projectors \of the transmission type comprising a compound of amyl acetate, alcohol, pyroxylin, a whitepigment, camphor, fusel oiland benzine as a light diffusing medium.

2. A picture screen for projectors of the transmission type comprising a pyroxylin compound and a tracing cloth through which light is successively transmitted.

3. A picture screen for projectors of the transmission type comprising a fabric coated a compound of amyl acetate, alcohol, pigment, camphor, fuse] with pyroxylin, a white oil and benzine.

4. A picture screen for ing a coatingcompounded of amyl acetate, alcohol, pyroxylin, a white pigment, camphor, fusel oil and. benzine, and a reflection reducing medium through which the light successively passes. 5. A picture screen for transmission type comprising 'a fabric having a coating compounded of amyl acetate, alcohol, pyroxylin, a white pigment, camphor, fusel oil and benzine, glass actingas a reflection reducing medium through which the light successively passes. In testimony whereof I have signed this specification this 26th day of August 1920.

. AUSTIN DAY BRIXEY.

projectors of the I and platinized projectors of the 1 transmission type comprising a fabric 'hav- 

